10 August 2017

Operation Danubian Mayfly

After four decades, 2012 was the first year to see the Danubian mayfly (Ephoron virgo) swarming above the Danube as an indicator of the significant increase in water quality. Millions of swarming mayflies has been reported in late July and August from many places between Budapest and Tahitótfalu since then every year. They have also been observed on one of the tributaries of the Danube, the Rába. But what is the reason for a nature film, dubbed Operation Mayfly? From what do we need to save them, are they already in danger?  

Since we would recommend to learn the answers from the film in brief the situation is the following: Ephoron virgo usually swarms after dusk, so all sources of artificial light on the river banks is a light-trap for them. Heading for these light sources, the female mayflies are dropping their batch of eggs on the ground instead of the water surface. These eggs will never hatch, so new generation of millions of mayflies will never be born. Lights on bridges is a more serious problem. While mayflies lay their eggs on the asphalt, they are perishing under the vehicles. In Hungary the ecological value of one Ephoron virgo mayfly is 10000 HUF, equivalent of $38USD, it is easy to calculate the ecological loss of the dead mayflies and their eggs. They are working on solving this problem, the Operation Mayfly film is about this struggle. 

So far I have no idea why there are beavers and coypues in this film, if anyone knows please let me know. Operation Mayfly has won the prize for the best document movie in the Ecological values of the Carpathian basin section on the third Internatonal Nature Film Festival in Gödöllő. We would like to take the chance and congratulate for the authors, Filmdzsungel Stúdió and  TZSM productions! 

If the subtitled (please press CC) youtube video is not working, you might find Operation mayfly on the below links:
  • http://teka.filmdzsungel.hu/dunavirag_mentoakcio/
  • http://www.mediaklikk.hu/video/a-dunavirag-mentoakcio-2/
  • https://vimeo.com/ondemand/adunaviragmentoakcio

20 October 2016

Eight gravel banks

It wasn't cheap, the two almost aerial photographs taken from the Visegrad castle costed 1700 HUF (~5 €). But totally worth it to climb up there to take a look on the upper tip of the Szentendrei Island and the new islands of Kismaros and Nagymaros. 

I would like to start with the least obtrusive thing: there is a recent archaeologic excavation on the Sibrik hill, Visegrád. If somebody is not familiar with this place there was a late Roman fortress on this hill and later it became the center of the Pilis county in Hungary. 

But let's go further:

Date, water level: 10.04.2015 Nagymaros 15 h -27cm

From the left there is the treeless river bank of Nagymaros, a long island and further right the Marosi Island. In the foreground there is the Szentendrei island and the vast gravel bank on its northern tip. And those small white dots aren't motorboats... 

...but gravel banks, eight in number. There are curious people on them. If a curious person has the height of 17,7-1,8 meters the furthermost gravel bank extends 60 meters into the Danube counting from the end of the Szentendrei Island. 

This end of the Szentendrei island is continuosly groving against the stream. More and more gravel bank emerges from the river. Without any human impact these gravel banks will join the body of the island. 

13 October 2016

Danubian Island of the year 2016

This is the fourth time the Donauinseln blog starts its poll for the Danubian Island of the year. You can vote for the three nominated islands between 13th October and 31th December 2015.

The aim of this poll is to focus attention on the mostly unknown islands of the Danube. Most of you probably visited the Seychelle Islands before any Danubian Island. As we stated this is the third poll, and we hope we have started a tradition and more-and-more people will learn about these islands across the Globe.

The winners so far (please note this is a Hungary-based blog):
2013. Kompkötő Island, Vác
2014. Helemba Island, Esztergom
2015. Kismarosi Island, Kismaros

This year our readers have selected two islands in the qualifying rounds. We start the introduction in alphabetical order, with the island we thought worthy enough to participate in the poll.

Former Fürdő Island, Budapest

Our first nominated island is really unique. This is the first nominated island from Budapest, and the first one which no longer exists. This tiny Danubian island could be found just north from The Árpád bridge, close to the left river bank. In the 18th century an icy flood devastated its trees. Since then it was only a gravel bank, rarely emerging from the river. Just before its final disappearance József Szabó visited the island and collected samples from more than 50 hot springs coming from the limestone hundred meters below.  He also sketched some Roman ruins, possibly remnants of a bath and archaeologists found an altar devoted to the god of the Danube. The Fürdő (Bath) Island has been dredged completely in 1874 due to river regulation works.

Szalki Island, Dunaújváros

The Szalki Island is located next to Dunaújváros, an industrial town in the middle of Hungary. This section of the Danube often changes course. On its predecessor there was a military camp in the beginning of the Roman era, 1st century. Out of its stones an abbey was built on this Island dedicated to Saint Pantaleon, who later gave the name to the nearby village: (Duna)Pentele. This abbey has been swallowed by the Danube in the 16th century. The Szalki island was later attached to the right banks of the Danube and in its side arm they built the ports of the city. Today the Szalki Island is a park, there is a campsite, famous for the rock festival called Rockmaraton. 

Zebegényi Island, Zebegény

Zebegényi Island can be found in the Danube bend. It is a real island on the Danube, which means it is uniquely surrounded by water all year. It is a rather young formation, not long ago it was only a gravel bar without plants on it. By this time this inaccessible strip of land became a popular place for the locals and the tourists as well in summertime. In wintertime it is a shelter for birds. This island was almost excavated during the construction works of the nearby Nagymaros hydroelectric dam, fortunately they stopped the construction, so this island could remain in the Danube Bend.

The poll will be closed at midnight 31th December 2016. The results will be available in the first post of the year 2017.

05 October 2016

Qualifying round of the "Danubian Island of the year 2016" voting

The time has come for the Danubian Island of the year voting. First time we had no qualifying rounds, but when we introduced the new system 10 islands were nominated in 2014. One year later it was 14 and this year we have a list of 17 Danubian islands. There is a fiction-island and a non-existent island in the list, the first is Senki-szigete (No-mans island) from a novel of Mór Jókai and the second is a former island of Budapest, disappeared in the 1870s. We have last year's second: the Zebegényi Island, two Pap islands (Priest Island) form Szentendre and Dunaújváros. Two islands within the boundries of Baja, a town in southern Hungary, and two not-well-known island from the Ráckevei-Danube (Kulcsár island) and southern Hungary (Gabriella island).

Two years ago we registered 436 votes duing the qualifying rounds, last year it has risen significally: 1716 votes, I hope we will surpass this in 2016. Remember, only the first two island qualifies into the finals. There will be another island added by the Donauinslen blog. This voting ends midnight, October 12th 2016. The finals will begin next evening!

So here are the nominated islands for 2016, please select your favourite:

22 July 2016

Hungary’s lowest high water mark

…Is located in the community of Gerjen, Tolna county, on a recently renewed house at the height of an ankle. All description mention that the high water mark from the year 1893 is located on the reformed church, but there is nowhere to be found.

The lowest high-water mark (photo: Gergő Szombathelyi)

If we take a closer look at the corners of the table and the missing screws it become most likely that the table has been removed from the church and had been replaced here. Maybe this was the original place of the mark an it was taken down by force from the same place before the renovation.

The date of the mark is also interesting. In Hungary it is a tradition to mark almost every exceptional high water with tables like this (the most famous are marking the 1838 icy flood in Budapest and several other places), but this seems to be the only one marking the flood of 27th february 1893.

The Danube caused much trouble in the community of Gerjen in the 1890s. On March 13th 1891 the levee broke nearby and the icy Danube flooded the village. Two years later the Danube visited Gerjen again. On February 27th 1893 floating ice has been stuck in the Várszeg river bend  4 kilometers downstream. Frozen water cemented the ice together and it functioned as a huge ice dam across the Danube. The rising water breached the levee again, and Gerjen has been flooded once more. This flood affected only a small territory, maybe that is why the only high water mark from year 1893 can only be found in Gerjen.

A flood ankle high (photo: Gergő Szombathelyi)

Despite the flood only reached the footing of the houses the community considered this flood remarkable enough to create a high-water mark to remember. They managed to create a hydrological rarity, the lowest high-water mark in Hungary.

Exact location.

Thanks for the idea, Gergő Szombathelyi!

28 April 2016


Since 1875 there is no flowing Danube water in Vienna's Heustadlwasser.  This was one of the many side-arms of the river now hiding in Prater park. Nowdays it is feeded by precipitation and ground water only. The Viennese river regulation measures has cut it off from the Danube and was mostly filled in with construction waste. The remaining parts can be found near the Ernst Happel stadium, it's lower third is cut through by the Prater's long alley.

Tina Blau: Heustadlwasser, Prater 1877

Despite the always windy weather in Vienna I happen to visit this Danube side arm in a period of calm. The sun has just risen and there was absolutely no wind. The Prater became slowly populated by runners, hikers, cyclists. There was a stillness in the air despite a highway is cutting through the park. These pictures (and the Danube as well) are reflecting this morning atmosphere. 

Plan of the Heustadlwasser in Vienna

If you visit Vienna it is worthy to explore these hidden side arms of the long lost Viennese Danube, reflecting the pre-1875 landscape.

10 February 2016

Ghost on the Danube

There is a spectre haunting these pictures. Visions of a long lost Danubian world coming alive again, like a ghost in an ancient manor house on Alexandru Cristian Beșliu's pictures. He uses Danube View, Google's new development like an expert, on which we can see the river's most scenic part just like as on board of a cruiser ship. Old postcards stick to the Danube View in the Iron Gates, where an island, Ada Kaleh sleeps her dream 33 meters below the Danube's surface.  

A view on the Danube from a porch of Ada Kaleh (imege: Alexandru Cristian Beșliu)
Alexandru Cristian Beșliu uploads these postcards pinned to the Danube View images to his own album on facebook. There is a minor distortion, because the Iron Gate I. hydroelectrical dam has been risen the Danube's surface since the pictures were taken, so there is at least 33 meters between the water level of Danube View and of the postcards. The main guidelines are the mountain ranges. 

Images of  the drowned island are not only shocking for those who lived there. We know of many villages like Ada Kaleh, drowned in a reservoir. We may get goose-bumps of the past little enclave of Turkey. The surrealistic view could be intensified with the divers stumbling on the bottom of the Danube.

Turkish houses on the Austrian walls (image by: Alexandru Cristian Beșliu)

Mosque transformed from a XVII. century Franciscan monastery with the old minaret in 1909. (image by: Alexandru Cristian Beșliu)

The mosque's new minaret. (image by: Alexandru Cristian Beșliu)

Mosque of Ada Kaleh, built in the 1720s (image by: Alexandru Cristian Beșliu)

A view on Ada Kaleh (image by: Alexandru Cristian Beșliu)

Many houses were build on the old fortress wall, due to the floods. (image by: Alexandru Cristian Beșliu)

Water sparkling in the moat (image by: Alexandru Cristian Beșliu)

Ruins of the fortress which gave the name of the island (Ada means island and Kale is fort in Turkish language) (image by: Alexandru Cristian Beșliu)
The port of Ada Kaleh (image by: Alexandru Cristian Beșliu)

Ghosts amongst the ruins... (image by: Alexandru Cristian Beșliu)

Characteristic Turkish tombstones in the cemetery, located in the eastern part of the fortress. (image byAlexandru Cristian Beșliu)

The island from the Romanian side - the blue road sign says: Ada Kaleh (image by: Alexandru Cristian Beșliu)

Let's hope there will be more pictures where these came from, and will be no more drowned village like Ada Kaleh! 

10 October 2015

Extreme low water on the Danube 2015

This year's hot summer combined with lack of precipitation have brought extreme low water levels on the Danube river. The blog asked its readers to send pictures if they found something interesting emerging from the riverbed, or they only find the landscape different from the usual. It looks like the low water will last well into autumn and with the drained catchment area we have to prepare for even lower water levels. 

Lowest water level measured at Budapest in 2015.

According to the summer forecasts the level of the Danube was far from the lowest value ever measured, but we advised not to leave our camera at home. During September and October the water level fell steadily to the value of 63 cm at Budapest which is only 12 cm above the lowest. 

But why are we interested in shallow water? - usually the floods draw more public attention. In times of low water Danubian depths reveals itself. Sand and gravel bars, holes in the riverbed, dykes etc. But while walking on the riverbanks you might find wrecks of ships, artifacts sunk long ago. The diving archaeologists are happy, they can work without their work-clothes. Europe's largest river shows us a different perspective, rather a desert than a river. 

There are also those who are not quite happy with low water. For example those shipmen who can not work for weeks in this situation. Or the environmentalists who are unable to help when they see tons of dying fish and shell in the drying river arms. 

So far the lowest value in Budapest ha been observed in 1947, 6th of November.  This was 51 cm. At the Vác gauging station it was -45 cm on the 29th of August. This is not a typo, the water level can go below the lowest point of the gauging station, then they have to extend it downwards. Unfortunately this is not a rare occurrence. 

If you happen to wander the banks of the Danube, do not forget to take pictures of the most interesting sights, and please send them (with the place, time and date) to our email address of facebook site

These are the received pictures so far (from earliest to latest): 

Jendricsné Vörös Dóra: Riverbank at Kisoroszi, 2015.07.17. 18:30 Budapest water level: 160 cm

Kurdi Imre: Felsőgöd beach. 2015.07.19. Budapest water level: 147 cm

Zirig Árpád: Mouth of the Morgó creek, Verőce 2015.07.22. 20:00 Budapest water level: 138 cm

Zirig Árpád: Mouth of the Morgó creek, Verőce 2015.07.22. 20:00 Budapest water level: 138 cm
Horváth Tibor: Alsógöd, volcanic tuff breaking the water. 2015.07.23. 22:30 Budapest water level: 139 cm 

Riverbank beneath the stone wall in Verőce.  2015.07.25. 17:00. Budapest water level: 139 cm 

Riverbank beneath the stone wall in Verőce.  2015.07.25. 17:00 Budapest water level: 139 cm 

Horváth Tibor: Alsógöd, volcanic tuff breaking the water. 2015.07.26. 9:40 PM. Budapest water level: 137 cm

 Szilágyi Csilla: Inn, Duna, Ilz - Passau: 2015.07.26.

Cigány sandbank, Mohács

Kurdi Imre: Sződliget 2015.07.28. Budapest water level: 135 cm

Kurdi Imre: Sződliget, mouth of the Sződi creek. 2015.07.28. Budapest water level: 135 cm

 Alsógöd beach, 2015 08.01. 9:00 Budapest water level: 139 cm

Oligocene clay in Alsógöd

  Dunakeszi ferry 2015.08.01. 9:30 Budapest water level: 139 cm

Mouth of the Csurgó creek in Dunakeszi. 2015.08.01. 9:30 Budapest water level: 139 cm

Gödi Island, dam. 2015.08.01. 15:30 Budapest water level: 147 cm

Gödi Island northern side 2015.08.01. 15:30 Budapest water level: 147 cm

 Kovács Miklós: Kacsa Island, Pócsmegyer 2015.08.05. Budapest water level: 145 cm

Kovács Miklós: Kacsa Island, Pócsmegyer 2015.08.05. Budapest water level: 145 cm

Kovács Miklós: Római-part, Budapest 2015.08.05. Budapest water level: 145 cm

Kovács Miklós: Inlet of the Palotai Island in Budapest 2015.08.05. Budapest water level: 145 cm

Wirker Károly: Süttő, Sandbanks near Madár Island 2015.08.11.

Sziget festival, Óbudai Island northern side 2015.08.13.

Schmidt Ádám József: Mouth of the Ördögárok in Budapest 2015.08.13. 10-11 AM Budapest water level: 107 cm

Vessző Katalin: Római part, Budapest 2015.08.14. morning. Budapest water level: 113 cm
Vessző Katalin: Római part, Budapest 2015.08.14. morning. Budapest water level: 113 cm

Vessző Katalin: Római part, Budapest 2015.08.14. morning. Budapest water level: 113 cm

Vessző Katalin: Gravel bar at Szentendre 2015.08.14. afternoon. Budapest water level: 114 cm

Kürti Gábor Dezső: Helembai gravel bar 2015.08.15. Budapest water level: 109 cm (Szob: w. l. -17 cm)

Tarr Dominik: Kis-Háros Island, Nagytétény 2015.08.16. 2-3 PM Budapest water level: 98 cm

Tarr Dominik: Kis-Háros Island, Nagytétény 2015.08.16. 2-3 PM Budapest water level: 98 cm

Becz Miklós: Dunaszekcső, riverbank full of loess cemented by calcium carbonate

Bucsek Tamás: Vác,  2015.09.20. evening. Budapest water level: 95 cm

 Horváth Tibor: Sand bar below the Megyeri bridge. 2015.09.22. Budapest water level: 76 cm 

Horváth Tibor: Alsógöd, the volcanic tuff outcrops in the Danube. 2015.09.22. Budapest water level: 76 cm 

Sand bar of the Szentendrei Island, 2015.10.04. Budapest water level: 72 cm

The Szobi and Helembai gravel bar, behind them the Helemba Island. 2015.10.05. Budapest water level: 67 cm